I just changed my tires for some awesome Sportmax GP-A' Race take off's
The tires are gripping fine.
However, I think because this is the first time I have mounted a 190 rear, I am getting some bad handling.
I am getting some head shake under heavy acceleration.
Is the 190 enough to screw up my great handling? Would it change my geometry that bad?

Back ground.
My bike is a completely stock 2005 VTR. 100,000km tomorrow.
99,946km today.

 

Yes tire size can drastically change the handling of the bike.

https://www.facebook.com/davemosstun...95028923840600

 

Is it a 50 or 55 profile?

 

190/60/17
I had to take off my hugger to fit it.

 

i had a 190/55 on my old vtr when i bought it. when i replaced the tyres i put the stock size 180 on it and i was surprised at how much better it tipped into corners and felt more stable.

I'd say you should go back to stock.

 

I ran those same take-offs for a few years. Its not just the size, but they are very triangular in shape and having track use sharpens that profile. This makes them twitchy at times.

On the track, the flat part of the tire makes a great contact patch leaned over, but on the street, you wont ever get there. So you are balancing on the narrow centerline so its twitchier. Tall rear tire also changes geometry to quicken steering.

You should also check the steering head bearings for proper adjustment. And these bikes are hyper sensative to worn tires.

 

Well... I heard "race take off"... The rest I ignored...

smokingjoe gave you the correct analysis... A track tire is a sharp profile tire, and when used it gets even sharper... The difference from a stock tire to a 190 with a 60 profile mounted on the stock 5.5 inch rim is huge... It's like standing the rear tire on a inch thick plank of wood... Not at all good for handling...

Plus, a race take off is only ever reliable on dry tarmac at decent temps, or if you have the skill to heat the tire up to working temp on other surfaces... On an otherwise bone stock VTR, I doubt you will find many possesing the skills to be able to do so, riding on normal roads...

So unless you are the next guy to challenge Pedrosa, Lorenzo, Rossi or Marqez, I'd stick to road or road/track tires if I where in your shoes... Less painfull in the end... The slightest rain shower with cold surface temps becomes a hazardous situation...

 

I have had them in a cold rain.
I did a stoppie with them that day.

They get good grip in the rain.

I'm no slouch. I can heat them up just fine..

Today was a hot day for the ride home. The tires heated up and got great grip and the bike handled way better.

I guess they are very poor cold weather tires.

I think I'll change them, even though they still had **** in the center, and the sides are still in great shape.

 

Yeah, I rode mine through a NYC winter and had a couple front end lockups. They get like bowling *****. I actually forgot I was running take offs when winter surprised me.

 

I don't doubt that... I'm no slouch either...

On a track I can get that type of tire up to temp, and use them to their potential, and I'm fairly sure you can as well...

But on a cold and slick road, in trafic, it's another matter... I can defiently say that I'm not able to consistently heat them up and keep them at working temps in all situations, to the point where I trust them... And I highly doubt you can do that either...

And that's when it gets dangerous... They grip fine when warm and you are moving... But a couple of stoplights, and a little slow in town manouvers, and they are right back to being bowling ***** (good description joe!) and if you get caught out from someone else doing something stupid, or you do something stupid yourself... With the tires in that state, you are probably going to loose grip, and potentially go down...

 

Yes, that is an issue. I will have to keep in mind that my tires actually suck when cold.
And cold could mean just about any time during my commute.

I ride to work every day, about 45 minutes. Mostly highway.
Little bit of inner city.

 

For me, I did the take off thing a few times, but was very happy to go back to instantly gummy dual compound sport touring tires.

I ride in daily in rain and snow if needed so couldnt really afford to rearend another taxicab. (it doesnt even leave a mark on them).

I figure I would need that extra traction (panic brake in a turn on the cold spot) at exactly the wrong time. Bridgestone 023 rears are only $130 new for a 190.

One spill cost more.